The novel complexing properties of macrocyclic polyamines with phosphate and oxalate anions, which we previously discovered, were tested against urinary calculi. An 18-membered hexaamine [18] ane N₆ and a 16-membered pentaamine [16] ane N₅ in vitro solubilized inorganic models of calculi (Ca₃ (PO₄)₂ and Ca (C₂O₄) and human urinary calculi in acidic solutions, implying that they may be useful as a new type of ingredient of irrigating fluids.